1. Field of the Invention
The present invention relates to a tube electrode stabilizer, and more particularly, to a tube electrode stabilizer for an EDM drilling.
2. Description and the Prior Art
EDM drilling requires more considerations than die sinker Electrical Discharge Machine (EDM) in terms of the tube electrode rigidity and the supply of the dielectric fluid. Typically, holes drilled on a work piece are deep and small, and a tube electrode is used to make the holes and supply dielectric fluid for EDM drilling. The fluid is pressurized to flush away the chips generated during EDM process.
For material removal, EDM discharge power is generated within the gap formed between the tube electrode and the work piece. Discharging creates pressure pushing a lower end of the tube electrode upward and causing the tube electrode to bend especially for a small diameter tube. The pressurized fluid supplied through the tube electrode and fraction between the tube electrode and guide also contribute to the bending of the tube electrode making the tube electrode unstable.
As shown in FIG. 4, a tube electrode 5 is clamped, rotated and inserted into a guide 6 near a work piece 7 by a collet 4 of a spindle 3. Due to the hollow and thin body of the tube electrode 5, for example, 400 mm long and 0.3 mm (and less) in diameter, the tube electrode 5 has very poor rigidity. The top and the center portions of the tube electrode 5 will swing outwardly when a bending force is encountered.
The swing of the top and the center portions of the tube electrode 5 affects the accuracy and efficiency of the electrode discharge machining. This invention is therefore to solve the above-mentioned shortcomings.
The primary objective of the present invention is to provide a tube electrode stabilizer for an EDM drilling comprising a stabilizer block and a mover. The stabilizer block has a concaved in shaped supporting wall that parallels to the traveling path of a tube electrode, and has a plurality of apertures interconnected to vacuuming connections to suck air. The mover is connected to the stabilizer block for approaching the tube electrode. Suction force pushes the tube electrode against the supporting wall to achieve stabilization of the tube electrode.
The secondary objective of the present invention is to provide a tube electrode stabilizer further having a sensor to detect whether the tube electrode is seated into the stabilizer block or not and to measure the available length of the tube electrode before or after drilling.